1. Technical Field of the Invention
This invention relates generally to touch screens used in electronic devices such as communication devices.
2. Description of Related Art
Display screens capable of touch input or touch screens, are used in a wide variety of electronic equipment including portable, or handheld, devices. Such handheld devices include personal digital assistants (PDA), CD players, MP3 players, DVD players, AM/FM radios. Each of these handheld devices includes one or more integrated circuits to provide the functionality of the device. Examples of touch screens include resistive touch screens and capacitive touch screens that include a display layer and sensing layer that is coupled to detect when a user has touched the screen and to resolve the location of the touch. By coordinating the location of the touch with the information displayed on the display layer at that location, a touch sensitive graphical user interface can be implemented.
Other examples of handheld devices include communication devices that operate in a communication system. Such communication systems range from national and/or international cellular telephone systems to the Internet to point-to-point in-home wireless networks to radio frequency identification (RFID) systems. Each type of communication system is constructed, and hence operates, in accordance with one or more communication standards. For instance, wireless communication systems may operate in accordance with one or more standards including, but not limited to, RFID, IEEE 802.11, Bluetooth, advanced mobile phone services (AMPS), digital AMPS, global system for mobile communications (GSM), code division multiple access (CDMA), local multi-point distribution systems (LMDS), multi-channel-multi-point distribution systems (MMDS), and/or variations thereof.
Depending on the type of wireless communication system, a wireless communication device, such as a cellular telephone, two-way radio, personal digital assistant (PDA), personal computer (PC), laptop computer, home entertainment equipment, RFID reader, RFID tag, et cetera communicates directly or indirectly with other wireless communication devices. For direct communications (also known as point-to-point communications), the participating wireless communication devices tune their receivers and transmitters to the same channel or channels (e.g., one of the plurality of radio frequency (RF) carriers of the wireless communication system) and communicate over that channel(s). For indirect wireless communications, each wireless communication device communicates directly with an associated base station (e.g., for cellular services) and/or an associated access point (e.g., for an in-home or in-building wireless network) via an assigned channel. To complete a communication connection between the wireless communication devices, the associated base stations and/or associated access points communicate with each other directly, via a system controller, via the public switch telephone network, via the Internet, and/or via some other wide area network.
The disadvantages of conventional approaches will be evident to one skilled in the art when presented the disclosure that follows.